Two mm-Wave VCOs in 28-nm UTBB FD-SOI CMOS

Two 60-GHz band voltage controlled oscillators (VCOs) designed in a 28-nm ultrathin body and buried oxide fully depleted silicon on insulator (UTBB FD-SOI) CMOS process are demonstrated and compared. Both VCOs have identical cross coupled nMOS cores and dissipate 3.15 mW from a 0.9-V supply. The first design uses a standard FET current source and achieves a figure of merit (FOM) of -181 dBc/Hz, whereas the second employs a filtered current source and achieves a state-of-the-art FOM of -187 dBc/Hz. The achieved 6-dB improvement demonstrates the efficiency of the filtering technique at millimeter wave frequencies and the feasibility of efficient low-phase noise designs in 28-nm UTBB FD-SOI CMOS. The active area of the filtered VCO is 90 μm × 180 μm and the standard VCO has an area of 80 μm × 110 μm.